From https://www.quantopian.com/open:
Can my algorithm trade leveraged ETFs?
No. Your algorithm may not trade leveraged ETFs. Any algorithm using a leveraged ETF (ProShares Ultra S&P500, 3x German Bund Futures ETF, etc.) will be disqualified.
What if my algorithm has leveraged ETFs in its universe, but they are not traded? At first you say "...may not trade..." but then you say "Any algorithm using a leveraged..." I may want to use leveraged ETFs but not trade them.